Preparation

In a large Dutch oven or soup pot, combine the penne, broth, onion, and garlic. Bring the mixture to a boil over medium-high heat. Reduce the heat to medium, cover, and cook, stirring every 1 to 2 minutes, until the pasta is tender and the liquid has almost been completely absorbed, about 12 minutes.
Stir in the pesto sauce, baby spinach, and peas and cook, stirring constantly, until the spinach is wilted and the peas are just heated through, another 3 minutes.
Serve immediately topped with fresh basil or store it in the refrigerator for up to 3 days. For best results, add another splash of vegetable broth when reheating the pasta.